Activation of p53 downmodulates TEF.

<p>(A) Nuclear extracts from NB4 cells cultured at the indicated temperatures and NTERA2 cells transfected with control or p53 shRNAs, were obtained and analyzed for the formation of protein-DNA binding complexes by EMSA. (B) The expression of TEF was analyzed in protein lysates from NB4 cells following activation of p53 by western blot. The levels of α-Tubulin were determined to assure equal loading. (C) HEK293T cells were co-transfected with a TEF promoter-luciferase reporter vector and with p53 cDNA or empty vector (pcDNA3). The mdm2 promoter was included as a positive control of response to p53. After 24 h of transfection, cell extracts were prepared and analyzed for the relative luciferase activity. Results were normalized for transfection efficiency with values obtained with pRSV-β-gal. All data points represent the means ± SD of three independent experiments.